Applying Design Patterns to Improve the Reliability of Embedded Systems through a Process of Architecture Migration

Designers of modern embedded control applications are often required to make necessary changes in the software architecture of an existing system in order to improve system performance and reliability. Such a migration process can present many challenges for an organization, not least because long-established (and possibly rather informal) working practices can be seen to be under threat. The research presented in this paper explores ways in which design patterns can be used to support the transition between informal "event triggered" system architectures and more predictable time-triggered alternatives. We have introduced a new pattern collection aimed to provide support to the developers in converting between event-triggered and time-triggered designs. The efficacy of the patterns is demonstrated through case studies in which applications initially based on event-triggered/pre-emptive architectures. The application of the patterns helped to transform to appropriate time-triggered architectures. The results obtained suggest that migration to time-triggered architecture using the proposed pattern collection may indeed help to improve system reliability.